The present invention relates to the field of laryngoscopes and, more specifically, to a laryngoscope assembly including a protective enclosure designed to preclude the possibility of transmitting a viral or bacterial infection from the instrument to the patient.
A laryngoscope is a hand held medical instrument used for visual examination of the larynx and trachea of a patient. It has a related use which is to facilitate the insertion of an endotracheal tube through the glottis and into the trachea for general anaesthesia during surgery. The procedure is referred to as endotracheal intubation.
The laryngoscope was invented in or about 1855 by Manual Garcia and introduced into medical practice in 1858 by Viennese surgeons Ludwig Turck and Johann Czermak. The instrument appears in two basic forms, an indirect laryngoscope and a direct laryngoscope. The former utilizes a mirror held near the back of the pharynx while a light is directed upon it from a reflector worn on the forehead of the examiner. The second type, a direct laryngoscope, is equipped with a built in illuminating device and a blade which moves the epiglottis and tongue forward to provide an unobstructed view of the larynx and the trachea. This application is concerned primarily with the second, or direct, type instrument.
The direct laryngoscope typically consists of a handle, a blade, and a connector fitting which holds the two together. The fitting is designed to permit quick attachment and detachment between the blade and the handle. A battery or batteries within the handle serve to power a light source. The latter may be a small incandescent lamp situated in the connector fitting or the upper portion of the handle. The lamp may be associated with a fiberoptic light conductor extending along the blade to a point located rearwardly of the tip portion of the blade. In certain older instruments, the incandescent lamp is mounted on the blade slightly to the rear of the tip portion and connected by wire to the battery in the handle.
Under current medical practices, instruments such as laryngoscopes should be sterilized after each usage to avoid the transmission of infection from one patient to another. Unfortunately, this precaution is not always followed with adequate thoroughness. Due to the construction of these instruments, particularly irregular sections of the blade and the connector fitting, there remains a residual risk of the presence of bacterial or viral infection sources in those areas and resulting transmission of infection from patient to patient.
U.S. Pat. No. 4,570,614 to Bauman discloses a laryngoscope with a disposable blade made partially of plastic material to avoid damage to the patient's upper front teeth from improper handling of the instrument. The patent also refers to a copending application disclosing a laryngoscope blade and disposable cover. The same inventor has also taken out three design patents showing three different configurations of disposable cover for specific laryngoscope blades. The design patents are Des. 242,396; Des. 242,397; and Des. 242,398. All of these disposable covers, as understood, cover the blade only and are open at the rear, risking exposure of the patient to possible contamination from the connector fitting and/or the handle due to inadequate sterilization.